The Oregon Groundwater Act was adopted in 1955 for the purpose of establishing a uniform system of administering groundwater rights in the State of Oregon. Modeled upon the 1909 Water Rights Act, which applied only to surface water, the Groundwater Act recognized water rights established prior to 1955 as vested rights subject to future adjudication and provided that groundwater rights would be administered in accordance with the doctrine of prior appropriation.
While the Groundwater Act required a state-issued permit for most groundwater rights established after the date of the act, the act provided that groundwater appropriations for domestic and certain other de minimus uses could be made without the need for a state-issued permit. Although the law did not require a permit for these so-called “exempt rights,” the law provided that exempt water rights would have the same legal status as any other water right and would similarly be regulated in accordance with the doctrine of prior appropriation.
Over years, the distinction between the groundwater and surface water administration has become increasingly blurred. The increased demand for both groundwater and surface water has resulted in the development of rules that are designed to prevent surface water usage from interfering with groundwater and vice versa. An understanding of the rules that govern interference decisions is essential in a variety of permitting and water distribution situations.
When it comes to interference questions, the general default rule is the Oregon Water Resources Department has the burden of demonstrating there is potential for substantial interference between groundwater and surface water. The foregoing rule is uniformly true with respect to wells that are located more than one direct horizontal mile from a surface water source that is not located within the boundaries of a critical groundwater area. There are, however, exceptions to the general rule that apply when a well is located less than one direct horizontal mile from a surface water source.
For example, when a well in an unconfined aquifer is located a direct horizontal distance of less than one-quarter mile from a surface water source, it is presumed the well has potential to cause substantial interference with surface water unless the water right applicant or appropriator can prove to the contrary. Similarly, when a well drawing from an unconfined aquifer is located a direct horizontal distance of less than one-mile from a surface water source, the existence of substantial interference is presumed if the well appropriates more than 5 cubic feet per/second or would result in stream depletion greater than 25% of the rate of appropriation over a thirty day period. There are certain other additional circumstances in which wells less than one direct horizontal mile from a surface water source will be presumed to have the potential for substantial interference.
What is interesting about the exceptions noted above is there are even exceptions to the exceptions. Specifically, the rule that potential for substantial interference will be presumed in many cases when a well is located less than one direct horizontal mile from a surface water sources does not apply when the well in question constitutes an “exempt water right”. Under Oregon law, wells drilled for domestic and/or certain other commercial or industrial uses are considered exempt water rights and may be established without a permit. While exempt water rights have the same legal status and can be regulated like any other water right in most cases, exempt water rights are specifically exempted from the rules that presume most water rights located less than one-mile from a surface water source have the potential for substantial interference.
As may be seen, the rules, exceptions, and exceptions to the exceptions that are used to determine whether a given well has the potential for substantial interference with a surface water source are quite complicated. A thorough knowledge and awareness of these rules is essential, particularly for individuals with wells located less than one-mile from a surface water source. However, the general rule of thumb to keep in mind is relatively simple: If your well is more than one direct horizontal mile from a surface water source, and not located in a critical ground water area, the Water Resources Dept has the burden of proving substantial interference. Conversely, if your well is located less than one direct horizontal mile from a surface water source, substantial interference is presumed and the well owner has the burden of overcoming the presumption.
For more information on the rules discussed in this article go to: http://www.sos.state.or.us/archives/rules OARS_600/OAR690/690_009.html